Germany is divided in 16 Bundesländer (Federated States). The architecture of castles differs from state to state as their purpose is different too. The most import terms regarding castles are Burg (Castle), Schloss (Palace), Festung (Fortress) and Herrenhaus (Manor).
List of castles and palaces in France.
List of castles and palaces in Denmark (Danmark).
List of castles and palaces in Czech Republic (Česká republika)
List of castles and palaces in Canada.
List of castles and palaces in Belgium.
Austria is divided into nine provinces. Eight of them are dominated by a lot of castles and fortresses, the ninth province named Vienna, which is also the capital city of Austria, is dominated by a lot of palais.
List of resources related to castles, palaces, manors, towers and fortresses all over the world.